The "Solar Age" didn't last very long and the support for projects of this type evaporated by the mid 1980's. As a result, there were few attempts to rigorously test the components of these types of homes. However, based upon our observations it appears that some of the components in the home had little value. For example:
The lesson here seems to be that the amount of solar heat gained and stored in our area is enough to make a large impact in areas with direct solar exposure and direct heat storage. However, it seems that the amount of solar heating available in our area is insufficient to overcome the heat loss that occurs when one attempt move the heat from one area to another.
I have also had the chance to visit and inspect many other solar homes and solar components and have found several other types of systems that tended to fail or result in limited value:
Solar systems also gained a poor reputation for some wrong reasons. The solar tax credits of the 1980's attracted some 'snake oil' sales people who only cared about the tax savings.
Solar systems also attracted a large number of amateurs who understood very little about construction and even less about solar systems. Many of their "inventions" performed very poorly.